<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Title</title>
</head>
<body>
	<button>1</button>
</body>
<script>
	const btn = document.querySelector("button");
	btn.onclick = function(){
		console.log(this);
	}
	btn.onclick();
</script>
</html>